#include <stdio.h>

int num[20][20] = {
	{ 8, 2,22,97,38,15, 0,40, 0,75, 4, 5, 7,78,52,12,50,77,91,8},
	{49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,4,56,62, 0},
	{81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,3,49,13,36,65},
	{52,70,95,23,4,60,11,42,69,24,68,56,1,32,56,71,37,2,36,91},
	{22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80},
	{24,47,32,60,99,3,45,2,44,75,33,53,78,36,84,20,35,17,12,50},
	{32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70},
	{67,26,20,68,2,62,12,20,95,63,94,39,63,8,40,91,66,49,94,21},
	{24,55,58,5,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72},
	{21,36,23,9,75,0,76,44,20,45,35,14,0,61,33,97,34,31,33,95},
	{78,17,53,28,22,75,31,67,15,94,3,80,4,62,16,14,9,53,56,92},
	{16,39,5,42,96,35,31,47,55,58,88,24,0,17,54,24,36,29,85,57},
	{86,56,0,48,35,71,89,7,5,44,44,37,44,60,21,58,51,54,17,58},
	{19,80,81,68,5,94,47,69,28,73,92,13,86,52,17,77,4,89,55,40},
	{4,52,8,83,97,35,99,16,7,97,57,32,16,26,26,79,33,27,98,66},
	{88,36,68,87,57,62,20,72,3,46,33,67,46,55,12,32,63,93,53,69},
	{4,42,16,73,38,25,39,11,24,94,72,18,8,46,29,32,40,62,76,36},
	{20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,4,36,16},
	{20,73,35,29,78,31,90,1,74,31,49,71,48,86,81,16,23,57,5,54},
	{1,70,54,71,83,51,54,69,16,92,33,48,61,43,52,1,89,19,67,48},
};

void product_u_d(int row,int col,unsigned int *largest) {
	int i = 0;
	unsigned int val = 0;
	for(i = row; i<row+4; i++) {
		if((*largest) < (val = (num[i][col]*num[i][col+1]*num[i][col+2]*num[i][col+3]))) {
			(*largest) = val;
		}
	}
}

void product_l_r(int row,int col,unsigned int *largest) {
	int i = 0;
	unsigned int val = 0;
	for(i = col;i<col+4;i++) {
		if((*largest) < (val = (num[row][i]*num[row+1][i]*num[row+2][i]*num[row+3][i]))) {
			(*largest) = val;
		}
	}
}

void product_diag(int row,int col,unsigned int *largest) {
	unsigned int val = 0;
	if((*largest) < (val = (num[row][col]*num[row+1][col+1]*num[row+2][col+2]*num[row+3][col+3]))) 
		(*largest) = val;
	
	col = col + 4;
	if((*largest) < (val = (num[row][col]*num[row+1][col-1]*num[row+2][col-2]*num[row+3][col-3]))) 
		(*largest) = val;
}

int main(int argc, char **argv) {
	int row,col;
	int largest = 0;

	for(row = 0; row<16;row++) {
		for(col = 0;col<16;col++) {
			product_u_d(row,col,&largest);
			product_l_r(row,col,&largest);
			product_diag(row,col,&largest);
		}
	}

	printf("%d \n",largest);
}
